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Heterotopic Auxiliary Rat Liver Transplantation With Flow-regulated Portal Vein Arterialization in Acute Hepatic Failure
Published on: September 13, 2014
Pediatric liver transplantation for urea cycle disorders and organic acidemias: United Network for Organ Sharing data
Emily R Perito1, Sue Rhee, John Paul Roberts
1Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California San Francisco, San Francisco, CA.
Insights
Liver transplantation for children with urea cycle disorders (UCDs) and organic acidemias (OAs) is prioritized regardless of disease severity. Early transplantation in children with UCDs/OAs is associated with increased post-transplant complications and developmental delays.
Area of Science:
- Pediatric Hepatology
- Transplant Surgery
- Metabolic Disorders
Background:
- Liver transplantation for urea cycle disorders (UCDs) and organic acidemias (OAs) presents unique challenges due to high-priority listing unrelated to disease severity.
- Limited national outcome data exist for pediatric liver transplantation in UCDs/OAs.
Purpose of the Study:
- To analyze national outcomes of pediatric liver transplantation for UCDs/OAs.
- To evaluate the impact of age at transplantation on graft survival, patient survival, and post-transplant morbidity.
Main Methods:
- Retrospective analysis of United Network for Organ Sharing (UNOS) data.
- Included liver-only recipients transplanted at <18 years old between 2002-2012.
- Excluded repeat transplants.
Main Results:
- Pediatric liver transplants for UCDs/OAs increased from 4.3% (2002-2005) to 7.4% (2010-2012).
- Graft and patient survival improved with increased age at transplantation (≥2 years vs. <2 years).
- Vascular thrombosis was a major cause of graft loss, particularly in younger children (<2 years).
- Children transplanted for UCDs/OAs showed higher rates of cognitive and motor delays.
Conclusions:
- Most liver transplants for UCDs/OAs occur in early childhood.
- Younger age at transplantation (<2 years) is associated with increased post-transplant morbidity, including graft loss and developmental delays.
- Further research is needed to determine optimal timing for liver transplantation in UCDs/OAs.
Abstract:
Decision making concerning liver transplantation is unique for children with urea cycle disorders (UCDs) and organic acidemias (OAs) because of their immediate high priority on the waiting list, which is not related to the severity of their disease. There are limited national outcome data on which recommendations about liver transplantation for UCDs or OAs can be based. This study was a retrospective analysis of United Network for Organ Sharing data for liver recipients who underwent transplantation at an age < 18 years in 2002-2012. Repeat transplants were excluded. Among the pediatric liver transplants, 5.4% were liver-only for UCDs/OAs. The proportion of transplants for UCDs/OAs increased from 4.3% in 2002-2005 to 7.4% in 2010-2012 (P < 0.001). Ninety-six percent were deceased donor transplants, and 59% of these patients underwent transplantation at <2 years of age. Graft survival improved as the age at transplant increased (P = 0.04). Within 5 years after transplantation, the graft survival rate was 78% for children < 2 years old at transplant and 88% for children ≥ 2 years old at transplant (P = 0.06). Vascular thrombosis caused 44% of the graft losses, and 65% of these losses occurred in children < 2 years old. Patient survival also improved as the age at transplant increased: the 5-year patient survival rate was 88% for children with UCDs/OAs who were <2 years old at transplant and 99% for children who were ≥2 years old at transplant (P = 0.006). At the last-follow-up (54 ± 34.4 months), children who underwent transplantation for UCDs/OAs were more likely to have cognitive and motor delays than children who underwent transplantation for other indications. Cognitive and motor delays for children with UCDs/OAs were associated with metabolic disorders, but they were not predicted by age or weight at transplant, sex, ethnicity, liver graft type (split versus whole), or hospitalization at transplant in univariate and multivariate analyses. In conclusion, most liver transplants for UCDs/OAs occur in early childhood. Further research on the benefits of early transplantation for patients with UCDs/OAs is needed because a younger age may increase posttransplant morbidity.
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